Macular Maps of Fluorescein Leakage during a 3-year Follow-up in Patients with Type 2 Diabetes Mellitus and Mild Non-proliferative Retinopathy

Abstract

Abstract: : Objective: To examine the 3 year alterations of the blood-retinal barrier occurring in the macular region in patients with type 2 diabetes mellitus and mild non-proliferative retinopathy. Methods: We classified 14 eyes of 14 patients with type 2 diabetes mellitus and mild non-proliferative retinopathy by 7 field stereoscopic fundus photography (levels 20 and 35 of Winsconsin grading) and examined them 7 times, at six-month intervals, by fundus photography, fluorescein angiography, retinal leakage analyzer (RLA-modified Scanning Laser Ophthalmoscope) and retinal thickness analyzer. Data from the group of individuals with diabetes were compared with those from a healthy control population. Results: Sites of abnormally increased fluorescein sodium leakage and areas of increased retinal thickness were detected in all eyes at baseline. Eyes of patients with HgA1c levels ≥7.5% at baseline or in four or more visits during the study presented more sites of abnormal leakage (p<0.001) and higher values of increased leakage (p<0.001). The sites of abnormal leakage appeared to be located in the retinal vasculature. When comparing the RLA-Leaking sites among the 7 examinations, there was a good correlation between the location of these sites, but a clear fluctuation in the percentages of increases. When analyzing each visit, no clear correlation was found between the number and location of the leaking sites and the areas of increased retinal thickness. Conclusions: A predominant alteration in the retina of patients with type 2 diabetes mellitus and mild non-proliferative retinopathy is the presence of leaking sites, indicating retinal vascular hyperpermeability. In this stage of the retinopathy this hyperpermeability is reversible and is clearly associated with poor glycemic control. Retinal edema is more stable and less dependent on variations in metabolic control.

Keywords: imaging methods (CT, FA, ICG, MRI, OCT, RTA, S • diabetic retinopathy